Fire extinguisher



R. W. AUSTIN FIRE EXTINGUISHER Filed June 9, 1958 Aug. 30, 1960INVENTOR. FabA 140577? BY WM and);

(47' 'OR/VEY United States Patent FIRE EXTINGUISHER Ralph 'W. Austin,Weymouth, Mass, assignor to Knight and Thomas Incorporated, Methuen,Mass, a corporation of Massachusetts Filed June 9, 1958, Ser. No.740,873

3 Claims. (Cl. 16931) This invention relates to a fire extinguisher.

The invention has for an object to provide a novel and improved fireextinguisher of the type containing a pressurized fire extinguishingmedium and which is characterized by novel valve means adapted toprovide an even and uniform flow of the fire extinguishing mediumtherethrough, and wherein provision is made for self-cleaning of thevalve in a novel and eflicient manner.

With this general object in view and such others as may hereinafterappear, the invention consists in the fire extinguisher as hereinafterdescribed and particularly defined in the claims at the end of thisspecification.

In the drawings illustrating the preferred embodiment of the invention:

Fig' 1 is a vertical cross sectional view of a fire extinguisherembodying the present invention and showing the valve unit in its closedposition;

'Fig. 2 is a plan view of the fire extinguisher;

Fig. 3 is a cross sectional detail view showing the valve unit in itsopen position;

Fig. 4 is an enlarged detail view in horizontal cross section taken onthe line 44 of Fig. 3;

Fig. 5 is an enlarged cross sectional view taken on the line 55 of Fig.4;

Fig. 6 is a horizontal cross section taken on the line 66 of Fig. 1 asviewed from the underside; and

Fig. 7 is a vertical section taken on the line 7--7 of Fig. 2.

In general the present invention contemplates a novel fire extinguisheradapted for use with various types of pressurized free-flowing fireextinguishing mediums, including liquid, gas or dry chemicals, such asdry carbon dioxide, which is provided with a novel and improved valveand with manually operated means for opening and closing the valve tocontrol the release of the pressurized medium. Prior valve controlledpressurized fire extinguishers of which I am aware are usually providedwith conventional valve structures having flat or beveled cooperatingsurfaces so that when certain types of fire extinguishing mediums areused, particularly those embodying dry chemicals such as dry powder, themedium may collect between the cooperating valve surfaces and hamper theseating efiiciency of the valve. As a result, to provide for efiicientoperation of such extinguishers, such prior valve units must bedisassembled and cleaned after use before the extinguisher is recharged.Furthermore, it has been found that with some fire extinguishingmediums, such prior valve structures cause, due to clogging,intermittent release and sputtering of the discharge fiow of thepressurized medium rather than an elficient, uniformly flowingdischarge.

In accordance with one feature of the present invention the fireextinguisher is provided with a novel valve unit designed forself-cleaning of the cooperating valve members when being moved from aninoperative to an operative position and return whereby to preventaccumulation of the fire extinguishing medium on and about the valveparts, consequently clogging the valve. In accordance with anotherfeature of the invention the pres-\ 2,950,762 Patented Aug. 30, 1960 cutvalve is designed to permit controlled expansion and release of thepressurized medium when the valve is opened so as to provide asubstantially uniform discharge flow of the fire extinguishing medium,free of sputtering.

Referring now to the drawings, the illustrated fire extinguisherincludes a container 10 sealed at its lower end in a conventionalmanner, as indicated at 12, and provided at its upper end with a closurearranged to detachably support a novel valve unit indicated generally at14. As herein shown, the upper end of the container 10 is provided withan annular flanged member 16 sealed thereto, the flanged member beingprovided with an upstanding, exteriorly threaded rim 18 defining themouth of the container 10. The valve unit 14 includes an upstandinghollow casing 20 having an outwardly flanged lower portion 22 providedwith an annular groove 24 for the reception of a sealing gasket 25. Thesealing gasket 26 bears against the upper edge of the rim 18, and anextension of the casing below the groove 24 is fitted into the interiorof the rim to center the unit. An interiorly threaded clamp member 28fitted over the lower portion 22 of the casing 21' is threadedly engagedwith the rim 1%, an inwardly extended flange 30 of the clamp member 28cooperating'with an outwardly extended flange 32 of the casing to clampthe gasket 26 into sealing relation with the mouth of the container.

The upstanding valve casing 2% is provided with a central vertical bore34 for the reception of a hollow valve stem 36 open at its lower end andwhich extends into a chamber 38 defined by a cup-shaped member 40threadedly secured in the lower end of the casing 29. The bottom wall ofthe member 4-0 communicates with the upper end of an elongated pipe 42provided with a screen 44 at its lower end and which extends to aposition adjacent the bottom of the container 16 in communication with apressurized fire extinguishing medium of any desired type.

The central bore 34 is of a diameter slightly greater than the diameterof the valve stem 36 providing an annular clearance space 46 thereabout,and the valve stem is fitted within and movable vertically relative to aplurality of annular sealing rings 48, 49 and 56 which are fitted intogrooves 52 formed in the interior Walls of let ports 54. The centralbore 34 communicates with a lateral bore or discharge outlet 56 formedin the casing 26 which is connected by a threaded adapter 58 to adischarge hose 6% having a nozzle 62. It will be observed that the boreis enlarged to provide an annular expansion chamber 64 adjacent thepoint of intersection of the lateral bore 56 and the vertical bore 34.

The hollow valve stem 36 is normally maintained in an upwardly extendedclosed position, as shown in Fig. 1, by a spring 66 extending betweenthe bottom wall of the cup-shaped member 4% and the underside of ashouldered portion of collar 63 formed integrally with the valve stem36. The upper face of the collar 68 bears against a portion of thecasing 20 to serve as a stop limiting the upward movement of the valvestem. When the valve stem is in its upwardly extended position theoutlet ports 54 are disposed between the upper sealing ring 48 and theintermediate sealing ring 4? and out of communication with the dischargeoutlet 56. The upper sealing ring 48 prevents escape of the pressurizedmedium through the upper end of the casing 243, and the intermediatesealing ring 49 prevents escape of the pressurized medium downwardly tothe discharge outlet. Likewise, the lower sealing ring 50 prevents thepressurized contents from leaking upwardly to the outlet 56. a

shaped to engage and depress the valve stem into the Y operativeposition shown in Fig. 3 when the handle is rocked downwardly. A secondhandle 76 pivotally mounted at 723 in a second lug 80 extended from theopposite side of the casing is provided to serve as a resistancehorizontal position to engage the underside of a cross bar 82 with theupper edge of the lug S6 enables the operator to manually squeeze theoverlying handle 7% downwardly toward the handle76 by placing the thumbon the free end of the handle 70 to control the depressing operation.

' The handle 76 may also serve as a carrying handle if desired. 'Inoperation the clamp member 28 may be unscrewed and the entire valvestructure removed as a unit arm, which when rocked upwardly to asubstantially in order to introduce the fire extinguishing medium into 7the mouth of the container whereupon the valve unit may be reassembledwith the mouth of the container. Thereafter, the container may bepressurized through a passageway 84 formed in the casing 20 and whichcommunicates with the interior of the container as shown in Fig. 6. Theupper end of the passageway 84 terminates in an interiorly threadedchamber provided with a plug 86, the chamber being formed in anexteriorly threaded flange portion 38 for connection to pressurizingapparatus, not shown.

From the above description it will be seen that in operation when thevalve stem 36 is pressed downwardly to align the radially slotted outletports 54 with the expansion chamber 6 and in operative relation to thedischarge 7 outlet 56 the pressurized contents of the container mayescape through the ports 54 and the discharge outlet 56 to be discliarged.v through the hose 60. The radially arranged elongated slots 54,together with the enlarged chamber 64,.permits uniform expansion andrelease of the pressurized contents to provide a substantially uniformflow or" the fire extinguishing medium through the hose 66 and thedischarge nozzle 62. The uniform flow of the extinguishing medium iseffected and maintained by the self-cleaning action of the valve duringits operation. The sealing rings 48, 49 and 50 efiect a wiping andcleaning action on the surfaces of the valve stem 36, and particularlythe slotted ports 54, during the upward'or downward movement of the stemas the valve is opened or closed in the manner herein described. It willbe observed that the'chamber 64 also serves to provide a clearance spaceadjacent the slots 54 when the valve is in an open position to assist inpreventing the valve from becoming clogged. It will be observed that theannular space 46 between the stem 36 and the bore 34 is open to thepressurized fire extinguishing medium between the lowermost sealing ring50 and the inner end of the bore when'the valve stem is depressed andthe'collar 68 is spaced therefrom. In order to prevent the material frombeing packed into this annular space by the collar 68 when the stem isreturned to its closed position, the collar is provided with a pluralityof cutouts 69 which comprise openings through which the medium cleanedfrom the valve stem by the cleaning action of the ring 50 may pass' andclogging of the valve prevented when the collar is moved into engagementwith the lower end of the bore as shown in the stem is returned to thecontainer. It will also be observed that any fire extinguishing materialaccumulated in the annular space between the intermediate sealing ring49 and the lower ring 50 during movement of the stem may pass into thechamber 64 and the discharge outlet 56 to be expelled by the pressurizedmedium when the 4 valve is opened. Also any material which may be wipedinto the annular space 46 between the sealing rings 48 and 49 findsrelief through the ports 54 when the stem is in its closed position. 7 i

The resilient sealing rings 48, 49, 56 may and preferably will comprisea synthetic rubber material, such as neoprene, of the type which may besubjected to extremes of high and low temperatures Without harmfuleffect. it will also be observed that the sealing rings present asmooth'iine seal with the stem 36 to provide'an etficient wiping action.t

While the preferred. embodiment of the invention has been hereinillustrated and described, it will be understood that the inventionmaybe embodied in other forms within the scope of the following claims.

Having thus described'the invention, What is claimed is:

1. A fire extinguisher comprising a container for holda pressurized fireextinguishing medium, and a valve unit removably connected thereto forcontrolling the release of said pressurized medium, said valve unitcomprising a valve casing having an elongatedbore and a discharge outletcommunicating with said bore, a hollow valve stem mounted forlongitudinal movement Within said bore, said valve stem being open atits lower end in direct communication with the interior of thepressurized container and having a plurality of relatively 'narrow,closely spaced, "elongated radial ports, said bore being slightly largerin diameter. than the diameter of the stem and provided with a pluralityof spaced annular resilient sealing rings in sealing engagement with thebore and the valve stem and providing an annular space between the boreand the stem, said sealing rings separating said annular space toprovide upper and lower annular spaces said bore being increased indiameter adjacent the discharge outlet to provide an annular expansionchamber, spring means for maintaining said valve stem in m extendedposition to present the radial ports out of alignment with said chamherand between two of said spaced sealing rings defining the upper annularspace to close the valve, and manually operated means engageable withthe upper closed end of said stem for depressing the same to present theradial ports in said lower annular space and in alignment with r saidexpansion chamber and said discharge outlet to open Fig. '5. Inoperation any material wiped from the stem by said .lowermostsealingring during the movement of V the valve and release the pressurizedmedium, said sealing rings effecting a wiping action on the stem duringmovement of the latter from a closed to an open position and returnwhereby to maintain the valve stem in a clean condition. 7

2. A fire extinguisher as defined in claim 1 wherein the material wipedfrom the.stem in-to the lower annular space is discharged when the valveis in its open position, and wherein the'material wiped from thesteminto the upper annular space finds relief through the ports when thevalve is in'itsi closed position. 7 v

3. A fire extinguisher as defined in claim 2' wherein the valve stem isprovided with a stop collar formed integrally therewith engageable witha portion of the valve casing defining the inner end of the bore tolimit the upward movement of the stem, said collar'having a plurality ofperipheral cutouts providing passageways between the interior of thecontainer and the annular space defined by the bore and the stem .belowthe lowermost sealing ringwhereby to provide relief for any materialwiped from the stem into said last-named annular'space and to preventpacking of the material into said" space by said collar.

References Cited in the file of this patent UNITED STATES PATENTS

